Why are we still waiting for a cure?

The latest post in the UAR staff blog series is written by our Science Writer, Dr Ian Le Guillou, who takes a look back on the progress made in treating cancer and the different tools doctors have at their disposal.

The cure for cancer has long been viewed as the holy grail of science, with riches and fame promised forwhoever finds it. The quest has been going on for well over a century with people devoting their entire lives tothe search, and so far everyone has failed.

At least, that’s the way cancer research is often thought of:

But while we’ve all been waiting foracure, scientists have been finding dozens of ways to tackle cancer - andthey come in many different forms:

Chemotherapy

The live-saving chemotherapy drugs that we have today can be traced back to one of humanity’s darkestinventions: chemical warfare. The first chemotherapy treatments began in the aftermath of the First WorldWar, when researchers discovered thatmustard gaswas effective at shrinking tumours in mice. Since then,there have been hundreds of drugs developed to kill or prevent cancer.Tamoxifen, for example, hascontributed to a 30% fall in the death rate of patients with breast cancer, saving thousands of lives each year,and is now being used to help prevent cancer from developing in the first place.

Antibodies

While chemotherapy had several major successes, biological therapies such asantibodiesofferedunprecedented precision in targeting cancer. These are proteins that are produced by an animal’s immunesystem to specifically target a certain aspect of the cancer cells. These took decades to get right – scientistsneeded to purify them (to produce monoclonal antibodies) and allow them to be accepted by the humanimmune system (to humanise them). Now we have treatments such asAvastin,rituximabandHerceptin.

Cancer vaccines

Although you can’t catch cancer from someone else, it can be caused by infections that are spread widely.This was first suspected in 1910, following research into unusual tumours found inchickens. Although thisresearch was initially met with scepticism, it triggered further studies that led to the discovery of thepapillomavirus that triggers growths in rabbits. This research directly led to theHPV vaccinebeing developeddecades later. The vaccine is now being given to teenage girls around the country and could preventthousands of cases of cervical cancer in the UK.

Stem cell transplants

Thought to be impossible as recently as the 1970s, thetransplant of blood stem cellswas first managed inpatients after research in dogs. It has since been a major factor in treating blood cancers such asleukaemiaandlymphoma. This makes it possible to use radiation to kill all of the patient’s stem cells in their bonemarrow. This destroys the cancer, but would kill the patient unless a transplant is available from a matchingdonor. This has created the need for charities such as theAnthony Nolan TrustandDelete Blood Cancer,who work to match patients with donors.

Genetic tests

Although they aren’t a treatment in themselves, genetic tests also save lives. Tests for variants of the BRCA1and BRCA2 gene that are associated withbreastandovariancancers are offered to about 7500 high-riskwomen a year in the UK. If the tests are positive, then that gives the women the chance to decide onpreventative measures and to ensure that they are closely monitored. Most famously these tests ledAngelinaJolieto have a double mastectomy last year to reduce her risk of cancer, a choice made by roughly 1000women each year in the UK.

There are now so many treatments available that it is hard to see the wood for the trees. So there isn’t a curefor cancer, but that’s no failure: in 1975, only 1 in 12 leukaemia patientssurvived for ten years, and just 30years later it was more than 1 in 3; cancer ten-year survival rates as a whole have doubled in the last 40years; ninety-six per cent of men now survive testicular cancer. The scale of change has transformed cancertreatments, making it unrecognisable from a generation ago.

I’ll leave you with thewordsof the chief executive of Cancer Research UK: “For some types of cancer, theword ‘cure’ is almost a reality”.

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